PETRUKHIN, Y. Natural Deduction for Three-Valued Regular Logics. Logic and Logical Philosophy, [S. l.], v. 26, n. 2, p. 197–206, 2016. DOI: 10.12775/LLP.2016.025. Disponível em: https://apcz.umk.pl/LLP/article/view/LLP.2016.025. Acesso em: 13 jun. 2024.